''Lepthoplosternum'' is a small

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

in the Callichthyinae subfamily of the armored catfish family.

Taxonomy

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

for this genus is ''Callichthys pectoralis''. The name is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''leptos'', meaning "thin", the Greek ''hoplon'', meaning "weapon", and the Greek ''sternon'', meaning "chest" or "sternum". ''L. stellatum'' and ''L. ucamara'' are hypothesized to form a partially unresolved

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tree ...

with ''L. pectorale'' and ''L. beni'', which are sister-species to each other. ''L. tordilho'' is sister to these four species and ''L. altamazonicum'' is the most basal species.

Species

There are currently six recognized species in this genus: * '' Lepthoplosternum altamazonicum'' R. E. dos Reis, 1997 * '' Lepthoplosternum beni'' R. E. dos Reis, 1997 * '' Lepthoplosternum pectorale'' (

Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858– ...

, 1895) * '' Lepthoplosternum stellatum'' R. E. dos Reis & Kaefer, 2005 * '' Lepthoplosternum tordilho'' R. E. dos Reis, 1997 * '' Lepthoplosternum ucamara'' R. E. dos Reis & Kaefer, 2005

Distribution and habitat

''Lepthoplosternum'' is widely distributed in cis-

Andean The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

south of the

Orinoco River The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

basin.

Ecology

''Lepthoplosternum'' species usually inhabit

lentic A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems (''lentic'' ref ...

or slow flowing water bodies and are often associated with marginal or floating vegetation. ''L. ucamara'' has even been found in

hypoxic Hypoxia means a lower than normal level of oxygen, and may refer to: Reduced or insufficient oxygen * Hypoxia (environmental), abnormally low oxygen content of a specific environment ** Hypoxia in fish, responses of fish to hypoxia * Hypoxia (medi ...

conditions. However, the type locality of ''L. stellatum'' is a stream, permanently flowing and well oxygenated.

Description

''Lepthoplosternum'' species are the smallest callichthyines (maximum

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

60.3 mm) and are easily recognized by two

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ...

: the lower lip with deep medial notch and a small, additional lateral notch forming fleshy projections on each side; and a single unbranched ray preceding the branched ones on the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

References

{{Taxonbar, from=Q6527930 Callichthyidae Fish of South America Catfish genera Taxa named by Roberto Esser dos Reis Freshwater fish genera